Impact of seaweeds extracts applied to grapevine cv Tempranillo

AIM AND METHODS: Grape withering is one of the key steps in the production of the most renowned red wines of the Valpolicella area, namely Amarone and Recioto. This practice, which was already used since Roman times, entails important modifications in grape composition and in the chemical and sensorial characteristics of the corresponding wines, especially in terms of aromatic profile. The aim of this research is evaluating the aromatic evolution during grape withering of the three main varieties used in Valpolicella wines: Corvina, Corvinone and Rondinella.Samples of the three varieties were analyzed at harvest and at different stages of withering, namely10%, 20% and 30% of weight loss. Free and glycosidically bound compounds were extracted and analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). RESULTS: For all the samples the data were normalized to eliminate the effect of concentration due to grape dehydration. Terpene content and evolution varied considerably in relationship to grape variety. Corvinone was richer in cyclic terpenes (including phellandrene, limonene, and cymene) and they decreased during withering.

Dormancy is a survival strategy for withstanding exposure to adverse environmental conditions.

Concerning sustainable Viticultures, the GiESCO notices the current confusion around the notions of:
– ‘integrated’ Viticulture which does not clearly set itself apart of classical so-called ‘reasoned’ Viticulture and involves series of certifications which are distinguishable with difficulty,
– ‘agro-ecological’ Viticulture which adds important elements of sustainability to ‘integrated’ Viticulture, without clarifying really the latter,
– ‘organic’ Viticulture which leans on some unbearable principles such as the opposition between chemical or natural products, with besides a frequent recourse to copper-products,
– ‘biodynamic Viticulture’ which recommends environment-friendly methods, but for very not scientifically verified.

Chitosan is gaining interest in red winemaking thanks to its ability to inhibit the development of Brettanomyces spp. yeast, or other undesired wine microbial threats. However, little is known about potential side-effects of its addition on the physico-chemical parameters of red wines.

Depuis le début des années 90, les vignerons des Caves Coopératives de l’Appellation “Côtes du Rhône” se sont penchés, au sein des structures de réflexion du Syndicat Général, sur deux axes de réflexion:
– Détermination des critères de sélection et de rémunération différenciée des apports de vendange;
– Organisation des sélections de vendanges sur la base des terroirs afin d’augmenter quantitativement le potentiel de sélection au sein de l’unité de production.